Optical module

ABSTRACT

An optical module includes a housing, and a main circuit board, an optical transmitting assembly, an optical receiving assembly, and an electrical connector that are disposed inside the housing. The optical transmitting assembly includes at least two sets of lasers, a transmitting-end optical assembly, and a transmitting-end optical fiber receptacle. The optical receiving assembly includes at least two sets of photoelectric detectors, a receiving-end optical assembly, and a receiving-end optical fiber receptacle. The electrical connector electrically connects the optical transmitting assembly and the optical receiving assembly to the main circuit board.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 16/227,691,filed Dec. 20, 2018 (allowed), which is based upon and claims priorityto Chinese Patent Application No. 201711488535.8, filed on Dec. 30,2017, the entire content of all of which are incorporated herein byreference.

FIELD OF THE DISCLOSURE

The present disclosure relates to the field of optical communicationand, more particularly, to an optical module.

BACKGROUND

With the rapid development of optical communication and the Internet inrecent years, users' demands for the network have also sharplyincreased, resulting in a surge of traffic in telecommunication trunknetworks, with traffic increasing at a rate of 50% to 80% each year. Inorder to adapt to the fast development of the network market, thetransmission speed of optical modules has also been rapidly increasing,and now 100G, 200G, and even 400G optical modules have appeared. Theincrease in the speed of optical modules poses significant problems suchas heat dissipation and miniaturization. The need to have more opticalcomponents laid out inside a smaller optical module housing whiledealing with the problem of heat dissipation has become a challenge inthe industry.

Chinese patent No. 201420189088.1 discloses a replaceable opticaltransmitting module and an optical transceiver having the same. Theoptical transmitting module contains a plurality of individually andindependently disposed optical subassemblies, and at least onepositioning mount disposed on the optical transceiver. This type ofoptical transmitting module is not able to accommodate more componentsbecause the quantity of lasers, chips, and optical assemblies that canbe accommodated is limited by the optical subassemblies and layout.Additionally, this type of optical transmitting module has poor heatdissipation and is difficult to assemble.

SUMMARY

One embodiment of the present disclosure provides an optical module. Theoptical module includes a housing. The optical module also includes amain circuit board, an optical transmitting assembly, an opticalreceiving assembly, and an electrical connector that are disposed insidethe housing. The optical transmitting assembly includes at least twosets of lasers, a transmitting-end optical assembly, and atransmitting-end optical fiber receptacle. The at least two sets oflasers are arranged in a stacked manner on planes parallel to the planeon which the main circuit board is located. The transmitting-end opticalassembly orients light emitted from the at least two sets of laserstoward the transmitting-end optical fiber receptacle. The opticalreceiving assembly includes at least two sets of photoelectricdetectors, a receiving-end optical assembly, and a receiving-end opticalfiber receptacle. The at least two sets of photoelectric detectors arearranged in a stacked manner on planes parallel to the plane on whichthe main circuit board is located. The receiving-end optical assemblyorients light from the receiving-end optical fiber receptacle toward theat least two sets of photoelectric detectors. The electrical connectorelectrically connects the optical transmitting assembly and opticalreceiving assembly to the main circuit board.

Another embodiment of the present disclosure provides an optical module.The optical module includes a housing. The optical module also includesa main circuit board, an optical transmitting assembly, an opticalreceiving assembly, and an electrical connector that are disposed insidethe housing. The optical transmitting assembly includes at least twosets of lasers, a transmitting-end substrate, a transmitting-end opticalassembly, and a transmitting-end optical fiber receptacle. The at leasttwo sets of lasers are disposed on the transmitting-end substrate. Thetransmitting-end optical assembly orients light emitted from the atleast two sets of lasers toward the transmitting-end optical fiberreceptacle. The transmitting-end substrates and the transmitting-endoptical fiber receptacle are fixed together. The optical receivingassembly includes at least two sets of photoelectric detectors, areceiving-end substrate, a receiving-end optical assembly, and areceiving-end optical fiber receptacle. The at least two sets ofphotoelectric detectors are disposed on the receiving-end substrate. Thereceiving-end optical assembly orients light from the receiving-endoptical fiber receptacle toward the at least two sets of photoelectricdetectors. The receiving-end substrate and the receiving-end opticalfiber receptacle are fixed together. The electrical connectorelectrically connects the optical transmitting assembly and opticalreceiving assembly to the main circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a perspective view of an optical modulein an embodiment of the present disclosure;

FIG. 2 is a structural diagram illustrating an interior of the opticalmodule in FIG. 1 after its housing is removed;

FIG. 3 is a top view of the interior of the optical module illustratedin FIG. 2 ;

FIG. 4 is a cross-sectional diagram along line B-B′ of the opticalmodule illustrated in FIG. 3 ; and

FIG. 5 is a cross-sectional diagram along line A-A′ of the opticalmodule illustrated in FIG. 3 .

DETAILED DESCRIPTION

The text below provides a detailed description of the present disclosurewith reference to specific embodiments illustrated in the attacheddrawings. However, these embodiments do not limit the presentdisclosure; the scope of protection for the present disclosure coverschanges made to the structure, method, or function by persons havingordinary skill in the art on the basis of these embodiments.

In order to facilitate the presentation of the drawings in the presentdisclosure, the sizes of certain structures or portions have beenenlarged relative to other structures or portions; therefore, thedrawings in the present disclosure are only for the purpose ofillustrating the basic structure of the subject matter of the presentdisclosure.

Additionally, terms in the text indicating relative spatial position,such as “upper,” “above,” “lower,” “below,” and so forth, are used forexplanatory purposes in describing the relationship between a unit orfeature depicted in a drawing with another unit or feature therein.Terms indicating relative spatial position may refer to positions otherthan those depicted in the drawings when a device is being used oroperated. For example, if a device shown in a drawing is flipped over, aunit which is described as being located “below” or “under” another unitor feature will be located “above” the other unit or feature. Therefore,the illustrative term “below” may include positions both above andbelow. A device may be oriented in other ways (rotated 90 degrees orfacing another direction), and descriptive terms that appear in the textand are related to space should be interpreted accordingly.

Moreover, it should be understood that although the terms “first,”“second,” etc. may be used in the text to describe various components orstructures, the objects being described should not be limited by theaforementioned terms. The aforementioned terms are only for the purposeof differentiating between the objects being described. For example, afirst surface may be referred to as a second surface, and, similarly, asecond surface may also be referred to as a first surface; this does notdeviate from the scope of protection for the present disclosure.

A purpose of the present disclosure is to provide an optical module thathas efficient heat dissipation capacity and a more rational spatiallayout.

FIG. 1 is a diagram illustrating a perspective view of an optical module100 in an exemplary embodiment of the present disclosure. FIG. 2 is astructural diagram illustrating an interior of the optical module 100 inFIG. 1 after its housing is removed. As illustrated in FIG. 1 and FIG. 2, the optical module 100 includes a housing 110. The optical module 100also includes a main circuit board 132, an optical transmitting assembly120, an optical receiving assembly 140, and an electrical connector thatare disposed inside the housing 110.

The housing 110 includes an upper housing 112 and a lower housing 114.The upper housing 112 and the lower housing 114 are assembled togetherto accommodate components such as the main circuit board 132, theoptical transmitting assembly 120, the optical receiving assembly 140,and the electrical connector. The main circuit board 132 is a rigidcircuit board on which electronic components are disposed, suchelectronic components including a capacitor, a resistor, a processingchip, etc. One end of the main circuit board 132 is connected to theelectrical connector, and the other end is a gold finger that is used toprovide an external electrical connection. The electrical connector mayinclude a flexible board, i.e., a flexible circuit board. In theembodiment illustrated in the drawings, the electrical connectorincludes a plurality of flexible connecting boards 134 and a rigidconnecting board 136.

FIG. 3 is a top view of the optical module 100 illustrated in FIG. 2 .FIG. 4 is a cross-sectional diagram along line B-B′ of the opticalmodule 100 illustrated in FIG. 3 . Referring to FIG. 3 and FIG. 4 , theoptical transmitting assembly 120 of the optical module 100 includes twosets of lasers 122, a transmitting-end substrate (including a firsttransmitting-end substrate 123 and a second transmitting-end substrate125), a transmitting-end fixing board 128, a transmitting-end opticalassembly 121, and a transmitting-end optical fiber receptacle 126.

In the embodiment illustrated in FIG. 4 , there are two sets of lasers,and each set of lasers 122 includes four lasers. In other exemplaryembodiments, the number of sets of lasers and the number of lasers ineach set may be adjusted as needed. One set of lasers 122 is disposed onthe first transmitting-end substrate 123, and the other set of lasers122 is disposed on the second transmitting-end substrate 125. The twosets of lasers 122 are arranged in a stacked manner on planes parallelto a plane on which the main circuit board 132 is located, i.e., thefirst transmitting-end substrate 123 and the second transmitting-endsubstrate 125 are disposed in a stacked manner. The optical transmittingassembly 120 and the optical receiving assembly 140 are arrangedside-by-side inside the housing 110. The two sets of lasers 122 arearranged one above the other inside the housing 110. A person withordinary skill in the art will now understand that between the lasersand the transmitting-end substrates, there may be other mediums for thepurpose of achieving better fixing, heat dissipation, etc. For example,a heat dissipating pad, a TEC (thermoelectric cooler), or othercomponents may be arranged between the lasers and the transmitting-endsubstrates.

The transmitting-end optical assembly 121 is configured to orient lightemitted from the two sets of lasers 122 toward the transmitting-endoptical fiber receptacle 126. The transmitting-end optical assembly 121mainly includes optical components such as a prism, a wavelengthdivision multiplexer, a lens, etc. In comparison with a connection madeusing an optical fiber, the transmitting-end optical assembly 121 doesnot require an optical fiber receptacle connection, which isinconvenient to assemble, and does not require a greater number ofreceptacles and separate components that occupy a large amount ofinternal space in the housing 110. Additionally, in the presentembodiment, the transmitting-end optical fiber receptacle 126 is aninterface used to connect with an assembly external to the opticalmodule 100.

Further, each transmitting-end substrate has two opposing surfaces. Thefirst transmitting-end substrate 123 is described as an example below. Asurface of the first transmitting-end substrate 123 is fitted and fixedon an inner surface of the upper housing 112. In the present embodiment,a good thermal connection between the first transmitting-end substrate123 and the upper housing 112 may be achieved by means of thermallyconductive adhesive or a thermally conductive pad. The other surface ofthe first transmitting-end substrate 123 is used to fix one set oflasers 122. The second transmitting-end substrate 125 and the firsttransmitting-end substrate 123 are the same except that one surface ofthe second transmitting-end substrate 125 is fitted and fixed on aninner surface of the lower housing 114. Thus, the two sets of lasers 122are disposed opposing one another. The two sets of lasers 122 arerelatively close to one another; accordingly, the first transmitting-endsubstrate 123 and the second transmitting-end substrate 125 arerelatively far from one another. Heat produced by the lasers 122 isradiated more easily because the first transmitting-end substrate 123and the second transmitting-end substrate 125 are both thermallyconnected to the housing 110. In other exemplary embodiments, the firsttransmitting-end substrate 123 and the second transmitting-end substrate125 may also be disposed close together. Still alternatively, the firsttransmitting-end substrate 123 and the second transmitting-end substrate125 may be integrated as a single transmitting-end substrate, with thetwo sets of lasers 122 disposed back-to-back on the two opposingsurfaces of the single transmitting-end substrate, respectively. Thefirst transmitting-end substrate 123 and the second transmitting-endsubstrate 125 may achieve thermal conductivity by means of connectionsbetween their side surfaces and the housing 110 or achieve heatdissipation by means of direct connections between the lasers and thehousing 110.

Additionally, the optical transmitting assembly 120 further includes thetransmitting-end fixing board 128 enclosing the two sets of lasers 122and the transmitting-end optical assembly 121. The transmitting-endfixing board 128 is fixed to the transmitting-end substrate and thetransmitting-end optical fiber receptacle 126. Thus, the lasers 122 andthe transmitting-end optical assembly 121 are all enclosed. The opticaltransmitting assembly 120 thus becomes a convenient-to-assemble unit.The optical transmitting assembly 120 and the housing 110 are connectedtogether by means of thermally conductive adhesive or a thermallyconductive pad. The quantity of transmitting-end fixing boards 128, howthe transmitting-end fixing boards are fixed together, and whichcomponents are enclosed thereby may be adjusted as needed.

FIG. 5 is a cross-sectional diagram along line A-A′ of the opticalmodule 100 illustrated in FIG. 3 . Referring to FIG. 3 and FIG. 5 , theoptical receiving assembly 140 of the optical module 100 includes atleast two sets of photoelectric detectors 142, a receiving-end substrate144, a receiving-end fixing board 148, a receiving-end optical assembly141, and a receiving-end optical fiber receptacle 146.

In the embodiment illustrated in FIG. 5 , there are two sets ofphotoelectric detectors 142, and each set of photoelectric detectors 142includes four photoelectric detectors. In other exemplary embodiments,the number of sets of photoelectric detectors and the number ofphotoelectric detectors in each set may be adjusted as needed. The twosets of photoelectric detectors 142 are disposed on the two opposingsurfaces of the receiving-end substrate 144. The two sets ofphotoelectric detectors 142 are arranged in a stacked manner on planesparallel to the plane on which the main circuit board 132 is located.The optical transmitting assembly 120 and the optical receiving assembly140 are respectively arranged side-by-side in the housing 110, and thetwo sets of photoelectric detectors 142 are arranged one above the otherinside the housing 110. The receiving-end optical assembly 141 is usedto orient light from the receiving-end optical fiber receptacle 146toward the two sets of photoelectric detectors 142. The receiving-endoptical assembly 141 mainly includes optical components such as a prism,a wavelength division multiplexer, a lens, etc. In comparison with aconnection made using an optical fiber, the receiving-end opticalassembly 141 does not require an optical fiber receptacle connection,which is inconvenient to assemble, and does not require a greater numberof receptacles and separate components, which occupy a large amount ofinternal space in the housing 110. In the present embodiment, thereceiving-end optical fiber receptacle 146 is an interface used toconnect to an assembly external to the optical module.

The optical receiving assembly 140 further includes the receiving-endfixing board 148 enclosing the two sets of photoelectric detectors 142and the receiving-end optical assembly 141. The receiving-end fixingboard 148 is fixed to the receiving-end substrate 144 and thereceiving-end optical fiber receptacle 146. Thus, the photoelectricdetectors 142 and the receiving-end optical assembly 141 are allenclosed. The optical receiving assembly 140 thus becomes aconvenient-to-assemble unit. The optical receiving assembly 140 and thehousing 110 are connected together by means of thermally conductiveadhesive or a thermally conductive pad. In the present embodiment, thereceiving-end substrate 144 is thermally connected to the housing 110 bymeans of the receiving-end fixing board 148. Of course, thereceiving-end substrate 144 may also be thermally connected to thehousing 110 directly through a side of an interior wall of the housing110 and not by means of the receiving-end fixing board 148.Alternatively, both of the above-described methods for the thermallyconnecting the receiving-end substrate 144 to the housing 110 may beused. The quantity of receiving-end fixing board 148, how thereceiving-end fixing boards are fixed together, and which components areenclosed thereby may be adjusted as needed.

Additionally, in this exemplary embodiment, the electrical connectordirectly connected between the optical receiving assembly 140 and themain circuit board 132 is a structure combining flexible and rigidboards. Specifically, the electrical connector includes two flexibleconnecting boards 134 and one rigid connecting board 136. The twoflexible connecting boards 134 on the side of the optical receivingassembly 140 are disposed parallel to one another. Each one of the twoflexible connecting boards 134 includes a first end and a second end.The first ends of the two flexible connecting boards 134 are connectedto the two opposing surfaces of the rigid connecting board 136,respectively. The second ends of the two flexible connecting boards 134are connected to the two opposing surfaces of the main circuit board132, respectively. As a result, a rigid-flexible-rigid connection isformed. An electrical connection between the flexible connecting boards134 and the main circuit board 132 may be achieved by means ofsoldering. An electrical connection between the flexible connectingboards 134 and the rigid connecting board 136 may be achieved by meansof combining flexible and rigid boards. Such connection has theadvantage of convenient assembly. An electrical connection between thephotoelectric detectors or the lasers (or monitoring photoelectricdetectors) and the flexible connecting boards may be achieved by meansof gold wires.

In the optical module 100 of the present exemplary embodiment, theoptical transmitting assembly 120 and the optical receiving assembly 140are arranged side-by-side, and the photoelectric detectors 142 andlasers 122 inside the optical transmitting assembly 120 and opticalreceiving assembly 140 are stacked one above the other. Thus, moreoptical and electronic components may be arranged in a limited space,thereby making it easier to achieve high-speed transmission.Additionally, since heat dissipation is achieved by means of fixing thephotoelectric detectors 142 and the lasers 122 to the substrates (thetransmitting-end substrate and the receiving-end substrate) that arethermally connected to the housing, the heat dissipation of the opticalmodule 100 will be effective. Moreover, the substrates and the opticalfiber receptacles (the transmitting-end optical fiber receptacle 126 andthe receiving-end optical fiber receptacle 146) are fixed together bymeans of the fixing boards (the transmitting-end fixing board 128 andthe receiving-end fixing board 148), thus facilitating optical pathcoupling and component assembly.

A person with ordinary skill in the art will now understand that thelayout of the components in the optical transmitting assembly 120 andthe layout of the components in the optical receiving assembly 140 areinterchangeable. In other words, the components in the opticaltransmitting assembly 120 may adopt the layout of the optical receivingassembly 140, and the components in the optical receiving assembly 140may adopt the layout of the optical transmitting assembly 120.Additionally, the sizes and external shapes of the optical transmittingassembly 120 and the optical receiving assembly 140 may be adjusted asneeded, thus enabling the optical transmitting assembly 120 and theoptical receiving assembly 140 to be conveniently fixed in the housing110 and to achieve better heat dissipation, etc. For example, theoptical transmitting assembly 120 may have a larger volume, or the shapeof the optical transmitting assembly 120 may be a non-cubic shape suchas two cubes of different volume or a trapezoidal body, etc.Alternatively, for convenient assembly and fixing, the opticaltransmitting assembly 120 and the optical receiving assembly 140 mayhave a click-fit connector that fixes the assemblies together.

With its rational components layout and heat dissipation design, theoptical module of the present disclosure may enable the housing of theoptical module to accommodate more optical and electronic components.Therefore, key technical challenges to an optical module for high-speedtransmission are resolved, making it possible to manufacture high-speedoptical modules.

In comparison with currently available technology, the presentdisclosure provides the following benefits. In the technical solutionprovided by the present disclosure, an optical transmitting assembly andan optical receiving assembly are assembled together after at least twosets of optoelectronic chips, such as lasers or photoelectric detectors,are arranged on each of the two assemblies. Thus, more components may bearranged in a limited space, thereby achieving a high-density layout andfacilitating a faster optical module transmission speed.

It should be understood that despite the descriptions of embodiments inthe specification, each embodiment does not entail only one independenttechnical solution. The specification is written this way simply for thesake of clarity. Persons having ordinary skill in the art should treatthe specification as a whole. The technical solutions in the embodimentsmay be combined in appropriate ways to form other embodiments that maybe understood by persons having ordinary skill in the art.

The series of detailed descriptions above is only intended to providespecific descriptions of feasible embodiments of the present disclosure.The detailed descriptions are not to be construed as limiting the scopeof protection for the present disclosure; all equivalent embodiments orchanges that are not detached from the techniques of the presentdisclosure in essence should fall under the scope of protection of thepresent invention.

What is claimed is:
 1. An optical module, comprising: a housing; and amain circuit board, an optical transmitting assembly and an electricalconnector that are disposed inside the housing, wherein the opticaltransmitting assembly comprises at least two sets of lasers and atransmitting-end optical assembly, the at least two sets of lasers beingarranged in a stacked manner on planes parallel to a plane on which themain circuit board is located, and the optical transmitting assemblycomprises two transmitting-end substrates, the two sets of lasers aredisposed on the two transmitting-end substrates respectively and betweenthe two transmitting-end substrates, the transmitting-end substratebeing thermally connected to the housing, the electrical connectorelectrically connects the optical transmitting assembly to the maincircuit board.
 2. The optical module of claim 1, wherein the opticaltransmitting assembly comprises a transmitting-end optical fiberreceptacle, the transmitting-end substrate and the transmitting-endoptical fiber receptacle being fixed together.
 3. The optical module ofclaim 2, wherein the housing comprises an upper housing and a lowerhousing, and the two transmitting-end substrates are a firsttransmitting-end substrate and a second transmitting-end substrate,respectively, one surface of the first transmitting-end substrate isthermally connected to the upper housing, and one set of lasers of thetwo sets of lasers is fixed on the other surface of the firsttransmitting-end substrate, and one surface of the secondtransmitting-end substrate is thermally connected to the lower housing,and the other set of lasers of the two sets of lasers is fixed on theother surface of the second transmitting-end substrate.
 4. The opticalmodule of claim 2, wherein the optical module comprises an opticalreceiving assembly, the optical receiving assembly and the opticaltransmitting assembly are arranged side-by-side inside the housing. 5.The optical module of claim 4, wherein the optical receiving assemblycomprises at least two sets of photoelectric detectors, a receiving-endoptical assembly, and a receiving-end optical fiber receptacle, the atleast two sets of photoelectric detectors being arranged in a stackedmanner on planes parallel to the plane on which the main circuit boardis located, and the receiving-end optical assembly orienting light fromthe receiving-end optical fiber receptacle toward the at least two setsof photoelectric detectors.
 6. The optical module of claim 5, whereinthe optical receiving assembly further comprises at least onereceiving-end substrate, the at least two sets of photoelectricdetectors being disposed on the receiving-end substrate, and thereceiving-end substrate being thermally connected to the housing.
 7. Theoptical module of claim 6, wherein the receiving-end substrate and thereceiving-end optical fiber receptacle are fixed together.
 8. Theoptical module of claim 5, wherein there are only two sets ofphotoelectric detectors, the optical receiving assembly comprises onereceiving-end substrate, the receiving-end substrate being located on aplane parallel to the plane on which the main circuit board is located,and the two sets of photoelectric detectors being disposed on the twoopposing surfaces of the receiving-end substrate, respectively.
 9. Theoptical module of claim 5, wherein the optical transmitting assemblyfurther comprises a transmitting-end fixing board enclosing the at leasttwo sets of lasers and the transmitting-end optical assembly, thetransmitting-end fixing board being fixed to the transmitting-endsubstrates and the transmitting-end optical fiber receptacle, and theoptical receiving assembly further comprises a receiving-end fixingboard enclosing the at least two sets of photoelectric detectors and thereceiving-end optical assembly, the receiving-end fixing board beingfixed to the receiving-end substrate and the receiving-end optical fiberreceptacle.
 10. The optical module of claim 5, wherein the electricalconnector comprises at least one flexible circuit board.
 11. The opticalmodule of claim 10, wherein there are two flexible circuit boards, theoptical transmitting assembly being electrically connected to the maincircuit board by means of the two flexible circuit boards.
 12. Theoptical module of claim 11, wherein the electrical connector furthercomprises a rigid connecting board, each one of the two flexibleconnecting boards including a first end on the side of the opticaltransmitting assembly and a second end, the first ends of the twoflexible circuit boards being connected to two opposing surfaces of therigid connecting board, respectively, and the second ends of the twoflexible circuit boards being connected to two opposing surfaces of themain circuit board, respectively.
 13. The optical module of claim 11,wherein a quantity of the at least one flexible circuit boards is two,the optical receiving assembly being electrically connected to the maincircuit board by means of the two flexible circuit boards.
 14. Theoptical module of claim 13, wherein the electrical connector furthercomprises a rigid connecting board, each one of the two flexibleconnecting boards including a first end on the side of the opticalreceiving assembly and a second end, the first ends of the two flexiblecircuit boards being connected to two opposing surfaces of the rigidconnecting board, respectively, and the second ends of the two flexiblecircuit boards being connected to two opposing surfaces of the maincircuit board, respectively.
 15. An optical module, comprising: ahousing; and a main circuit board, an optical transmitting assembly, anoptical receiving assembly, and an electrical connector that aredisposed inside the housing, wherein the optical transmitting assemblycomprises at least two sets of lasers, a transmitting-end substrate, atransmitting-end optical assembly, and a transmitting-end optical fiberreceptacle, the at least two sets of lasers being disposed on thetransmitting-end substrate, and the transmitting-end substrate and thetransmitting-end optical fiber receptacle being fixed together; the twosets of lasers are disposed on opposite sides of the transmitting-endsubstrate, the electrical connector electrically connects the opticaltransmitting assembly and the optical receiving assembly to the maincircuit board.
 16. The optical module of claim 15, wherein the opticaltransmitting assembly further comprises a transmitting-end fixing board,the transmitting-end fixing board being fixed to the transmitting-endsubstrate, the transmitting-end substrate being thermally connected tothe housing by means of the transmitting-end fixing board.
 17. Theoptical module of claim 16, wherein the optical transmitting assembly isconnected to the housing by means of thermally conductive adhesive or athermally conductive pad.
 18. The optical module of claim 15, whereinthe optical receiving assembly comprises a receiving-end fixing boardenclosing at least two sets of photoelectric detectors and areceiving-end optical assembly, the receiving-end fixing board beingfixed to a receiving-end substrate and a receiving-end optical fiberreceptacle.
 19. The optical module of claim 15, wherein the at least twosets of lasers are electrical connected to two opposite surfaces of themain circuit board, respectively.
 20. The optical module of claim 15,wherein the optical transmitting assembly and the optical receivingassembly are fixed together by means of a click-fit connector.